1. Field of the Invention
The present invention relates to a method of manufacturing electron emitting devices and a method of manufacturing an image display apparatus.
2. Related Background Art
Most of image display apparatuses used presently are cathode ray tubes (CRT's). In place of CRT's, a number of flat panel displays have been developed, studied and are commercially available, such as liquid crystal display (LCD), plasma display panel (PDP), electro luminescence display (ELD) and field emission display (FED).
An electron emitting device is used for some of the above-described display apparatuses. For example, in manufacturing an electron emitting device, a conductive thin film including an electron emitting region is formed by directly depositing conductive material on an insulating substrate by deposition techniques such as vapor deposition and sputtering. Another recent method is to dispense liquid droplets containing conductive thin film material to an insulating substrate by an ink jet method. This ink jet method does not require a vacuum system and can form a large screen device. In order to form a good electron emitting device by preventing liquid droplets from being dispensed in an ink jet manner to positions different from predetermined positions of an insulating substrate, the substrate is processed in advance with hydrophobic process agent of hexamethylsilazane (refer to Japanese Patent Application Laid-open No. 9-069334). Other methods of manufacturing a good electron emitting device include a method of adjusting the surface energy of a substrate to which liquid droplets are dispensed to have a desired surface energy by using silane coupling agent such as dimethylethoxysilane (Japanese Patent Application Laid-open No. 10-326559) or by using silane coupling agent having only a single hydrolysis group (Japanese Patent Application Laid-open No. 2000-182513).
With the method of dispensing liquid droplets after the hydrophobic process using hexamethylsilazane, however, a hydrophobic process is difficult to be performed without variations or hydrophobicity becomes too large so that liquid droplets may be shrunk, being unable to form a good electron emitting device. With the method of dispensing liquid droplets after the hydrophobic process using silane coupling agent such as dimethylethoxysilane, hydrophobicity is insufficient so that the liquid droplets may flow and expand to positions different from desired positions of a substrate or a hydrophobic process is difficult to be performed without variations, being unable to form a good electron emitting device. With the method of dispensing liquid droplets after the hydrophobic process using silane coupling agent having only a single hydrolysis group, there is only one bond between the substrate and silane coupling agent and there is no bond between silane coupling agents coupled to the substrate. Hydrophobicity is therefore insufficient so that the liquid droplets may flow and expand to positions different from desired positions of a substrate. With this method, it is therefore difficult to manufacture an electron emitting device.